Does storage temperature affect the acidity level of Orange Juice?

Broad Question:

Does storage temperature affect the acidity level of Orange Juice?

Specific Question:

Does a higher or lower storage temperature affect the acidity level of Orange Juice when changed from the refrigerator temperature of 35-38°F?

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Variables:

Independent Variable: Storage Temperature

Dependent Variable: acidity level (pH)

Variables That Need To Be Controlled:

Starting with the same acidity level

5 trials for each storage area

The temperature of the cupboard

The temperature of the refrigerator

The temperature of the cooler

Hypothesis:

I hypothesis that the 5-day trial with the Orange Juice in the cooler will have the average most change in the acidity level, followed by the cupboard, and then the refrigerator. The refrigerator should not change from the original acidity because those will be at the same temperature.

Graph of Hypothesis:

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Experimental Design:

My experiment will be conducted at home. I will have each storage area that I need, including a cupboard, a refrigerator, and a cooler. I will not have anyone else involved in my experiment. I will complete it on my own. To get enough reliable information, I will be completing five trials for my experiment. I will complete one every night. I will be sure to let each amount of time be the same so everything shall end up the same. When I am conducting my experiment, I will have a data table printed out so that I can record my data. I will be able to put it on the computer later. To document the process, I will use my camera. My camera has a memory card that I will be able to use and then transfer the pictures to my computer. I can then send the pictures to my Google Docs account. I will then have them for use on my wiki and my display board if it’s needed.

Materials List:

pH paper (measures acidity level)

Orange Juice ( any brand, as long as for each trial it is the same brand)

Three Storage Area’s ( different temperatures)

Thermometer (three)

Clear Plastic Cups (must have at least three)

Detailed Procedure:

1. Gather materials at home.
2. Get out three of your plastic cups.
3. Put Orange Juice in each cup.
4. Put pH paper in each cup of Orange Juice.
5. Record the color of the paper. ( There will be a key to tell you what number the color stands for.)
6. Take paper out of all three cups after data is recorded.
7. Next, place one cup in a cupboard with one thermometer, another in the refrigerator with a thermometer, and the last one in a cooler with a thermometer. ( be sure that there is 6 cups of ice in the cooler.)
8. Record the time as to when all the cups were put in their storage area.
9. Wait overnight.
10. The next morning, record what time it is and take the Orange Juice out of their storage places.
11. Be sure to put the pH paper in each cup quickly and then record the color. (As said before, there will be a key to tell you the number as to what the color stands for.)
12. Repeat steps 2-11 for the next four nights for a total of 5 trials in all.

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Background Research:

	Early Spanish explorers planted the first orange trees in St. Augustine, Florida in the 1500’s Perfect environment for trees to grow in (Florida) First Orange Grove 1830 on Merritt Island Approximately 80% of Americas Orange Juice is from Florida Florida is second only to Brazil in global orange production Orange Juice is one of Americas most healthiest morning beverages
	Seed known as pip White, thread like substance inside peel is called pith many types of Oranges: Blood, Navel, Persian, Valencia, Clementine, and Honeybell Brazil, US, and Mexico largest producers of Oranges very acidic fruit with high pH level grow to a height of about 10 meters with evergreen leaves that are alternate and oval, Fruit is considered a type of berry name Orange comes from Sanskirt language
	Acid is a compound ( a compound is a substance that is made up of multiple substances) that releases hydrogen ions when dissolved in water Acid originates from the Latin word acere which means sour and therefore that works because acids are very sour non edible acids can burn or poison the strongest acid is hydrochloric acid (stomach acid) one type of acid found in oranges is citric acid ( comes from citric fruits)
	Oranges are an excellent source of Vitamin C serve 116.2% of Vitamin C based on % Daily Value of nutrition Oranges originated from Asia thousands of years ago Sweet Oranges: hybrid species, smaller in size, more aromatic flavor Bitter Oranges: often used for jam or marmalade, zest serves as the flavoring for some liqueurs

References:

"Acidic Fruit | Orange Juice Nutrition Facts." http://www.orangejuicenutritionfacts.info/tag/acidic-fruit/. Wordpress, 2010. Web. 18 Jan. 2012.


Karpelenia, Jenny. Acids and Bases. Logan, IA: Perfection Learning Corporation, 2006. Print.


Mathis, Karen. "Orange Juice Facts." http://www.orangejuicefacts.com/. N.p., Web. 18 Jan. 2012.

"WHFoods: Oranges." http://www.whfoods.com/genpage.php?tname=foodspice&dbid=37. The George Mateljan Foundation, 2001-2012. Web. 19 Jan. 2012.

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Results:

Graphs:

Photos:

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Data Analysis:

Conclusion:

The original purpose of this experiment was to see, how the temperature of a storage area, would affect the acidity level of orange juice. The results of the experiment were that from the starting acidity of about 2.5 pH, the orange juice in the cupboard changed the most. The average change of the five separate cups was 3.2 pH. The change goes up 0.7 pH. Next came the five from the refrigerator with an average of 2.9 pH and a difference of 0.4 pH. Lastly, was the cooler with an average of 2.3 pH for the five cups and a difference of 0.2 pH.

Discussion:

My hypothesis was that the cooler would cause the most change in pH level of orange juice, followed by the cupboard and then the refrigerator. My results do not support my hypothesis. In the results the cupboard had the greatest pH change, followed by the refrigerator and lastly the cooler. There is a relationship between the independent and dependent variable. The independent variable was the storage temperature and the dependent variable was the acidity level (pH). The acidity level did change according to the storage area. It seemed the colder the area, the lower the acidity. Some patterns or trends in my data are with all my data. All of the acidity levels for each area are mostly the same, possibly off by .5 or just 1. For the cupboard, the acidity levels were 3 pH, 3.5 pH, 3 pH, 3.5 pH, and 3 pH.
I think the tests I did went smoothly. Setting everything up went well. I just put the Orange Juice into 5 separate cups (15 total cups, 5 in the 3 areas) to start and then i let everything sit for 5 days. If i could improve my experiment, i would have gotten all of my materials sooner. At first the materials that i had would not have worked for my experiment. So, i had to get new materials that would work for my experiment. To further extend my experiment I could see if leaving it out longer would make it so the Orange Juice would separate or even evaporate. Orange Juice is mostly made up of water and if it evaporated it wouldn't leave much but pulp.

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